In the installation of the Christmas tree, the Christmas tree includes trunk, branches, and a lot of decorative lighting hanging on the branches. Because some Christmas tree is large and relatively high, the decorative lighting on the Christmas tree is divided into multiple sections from the bottom to the top. During the installation, an ordinary adapter is used to energize the lighting on the Christmas tree. However, due to the dense arrangement of components on the Christmas tree, it is difficult to install the adapter in the actual circuit connection, so a large amount of time is wasted in assembly and improvement is needed.